Answer
The difference between the consecutive terms is $4$.
Work Step by Step
Here, $a_2-a_1=[4(2)-3]]-[4(1)-3]=4;\\ a_3-a_2=[4(3)-3]]-[4(2)-3]=4;\\a_4-a_3=[4(4)-3]]-[4(3)-3]=4;\\a_5-a_4=[4(5)-3]]-[4(4)-3]=4$
It has been seen that the difference between the consecutive terms is $4$